I was reading the following sentence:
Die meisten Studierenden hielten den Präsidenten für unglaubwürdig.
and I read on wiktionary that
halten + für means to consider, to regard
but I know from previous studies that für is the preposition "for", so my question is:
What is the use for the preposition für? Is it simply an element of Old German that has been accepted with time?